Difference between revisions of "DRIVE50"

From Land Boards Wiki
Jump to navigation Jump to search
Line 8: Line 8:
 
* Card is non-inverting
 
* Card is non-inverting
 
* BNC or SMA connector
 
* BNC or SMA connector
* 3.3V or 5V
+
* 3V-5V power
 
* 3-pin right angle 0.1" pitch input connector
 
* 3-pin right angle 0.1" pitch input connector
 +
 +
== Driver ==
 +
 +
* 5x paralleled [http://cva.stanford.edu/classes/cs99s/datasheets/74AC14.pdf 74AC14] drivers
 +
** 24mA per pin
 +
* Input has single buffer stage
 +
* 3.3V, 250 Ohm resistors (/5) for 50 Ohm output
 +
* Short-circuit proof
 +
* 5V, 250 Ohms to ground is 20 mA (pins are rated for 24 mA
  
 
== Test ==
 
== Test ==

Revision as of 15:43, 6 July 2022

DRIVE50 FRONT 3D.png

50 Ohm Driver Card

  • Line driver
  • 50 or 75 Ohm output impedance
  • 10K pull-up on input
  • Card is non-inverting
  • BNC or SMA connector
  • 3V-5V power
  • 3-pin right angle 0.1" pitch input connector

Driver

  • 5x paralleled 74AC14 drivers
    • 24mA per pin
  • Input has single buffer stage
  • 3.3V, 250 Ohm resistors (/5) for 50 Ohm output
  • Short-circuit proof
  • 5V, 250 Ohms to ground is 20 mA (pins are rated for 24 mA

Test

  • Supply Vcc 3.3V to 5V and ground
  • Input is pulled up to Vcc
  • Measure output with BNC T
    • Should be 1/2 of Vcc with 50 Ohm terminator
    • Should be Vcc without terminator

Mechanicals

DRIVE50 MECHS REV1.PNG

Assembly Sheet